The Genetics of Behavior PDF

The Genetics of Behavior DONNA LEA P. BUENDIA  Mendelian Genetics  Gregor Mendel – a late-19th-century monk who thought that inheritance was a blending process in which properties of the sperm and the egg simply mixed, like two colors of paint.  Genes – basic physical an...

The Genetics of Behavior DONNA LEA P. BUENDIA  Mendelian Genetics  Gregor Mendel – a late-19th-century monk who thought that inheritance was a blending process in which properties of the sperm and the egg simply mixed, like two colors of paint.  Genes – basic physical and functional unit of heredity  DNA (Deoxyribonucleic acid) – it contains the genetic code of organisms  RNA (Ribonucleic acid) - convert the information stored in DNA into proteins  Cont.  Homozygous – identical pair of genes on the two chromosomes  Heterozygous – unmatched pair of genes  Dominant gene – shows a strong effect in either homozygous or heterozygous condition  Recessive gene – shows its effect only in the homozygous conditions  Sex-Linked and Sex-Limited Genes  These are the genes located on the sex chromosomes.  Examples of Sex-Linked Traits: 1. Hemophilia 2. Red-green color blindness 3. Baldness  Heredity and Environment  3 Kinds of Twins 1. Monozygotic Twins – identical twins 2. Dizygotic Twins – fraternal twins 3. Siamese Twins – conjoined twins  Phenylketonuria (PKU) – genetic inability to metabolize the amino acid phenylalanine, can lead to mental retardation.  The Evolution of Behavior  Evolution – change over generations in the frequencies of various genes in a population  Common Misunderstandings About Evolution Does the use or disuse of some structure or behavior cause an evolutionary increase or decrease in that feature? (Lamarckian evolution) Have humans stopped evolving? Does evolution mean improvement?  Evolutionary Psychology  Deals with how behaviors have evolved, especially social behaviors.  Group Selection – altruistic groups survive better than less cooperative ones.  Reciprocal altruism – the idea that individuals help those who will return the favor (“You scratch my back, I’ll scratch yours.”)  Kin Selection – selection for a gene that benefits the individual’s relatives.